Administer carcinogens to animals by standard techniques including controlled feeding, parenteral administration, skin painting, intragastric intubation, intracheal instillation, and other techniques as required and approved by the Project Officer. Maintain animals for the time required by the experiments, under optimum husbandry conditions as specified by the Project Officer. Perform histopathological and pathological examinations of all animals. Fixed tissues as specified for each experiment will be stored as such for future reference as required. Organs will be grouped by standard procedures in paraffin blocks, and slides, stained with hematoxylin and eosin or other stains as required. Other activities related to carcinogenesis studies will include the preparation, maintenance, and treatment of tissue cultures; isolation of cells and subcellular constituents; and determination of various biochemical parameters under the direction of, and collaboration with, the Project Officer and Assistant Project Officers.